Problem: Evaluate the following expression when $d = 4$ and $c = 3$. $9$ $d$ $ + 8$ $c$ $ - 10$
Solution: Substitute $4$ for ${d}$ and $3$ for ${c}$ $ = 9{(4)} + 8{(3)} - 10 $ $ = 36 + 24 - 10 $ $ = 50$